Cultivable Anaerobic Microbiota of Infected Root Canals

1Division of Oral Ecology and Biochemistry, Tohoku University Graduate School of Dentistry, Sendai 980-8575, Japan2Division of Periodontology and Endodontology, Tohoku University Graduate School of Dentistry, Sendai 980-8575, Japan3Division of Advanced Prosthetic Dentistry, Tohoku University Graduate School of Dentistry, Sendai 980-8575, Japan4Division of Pediatric Dentistry, Niigata University Graduate School of Medical and Dental Sciences, Niigata 951-8514, Japan

Received 15 December 2011; Revised 30 January 2012; Accepted 5 February 2012

Abstract

Objective. Periapical periodontitis is an infectious and inflammatory disease of the periapical tissues caused by oral bacteria invading the root canal. In the present study, profiling of the microbiota in infected root canals was performed using anaerobic culture and molecular biological techniques for bacterial identification. Methods. Informed consent was obtained from all subjects (age ranges, 34–71 years). Nine infected root canals with periapical lesions from 7 subjects were included. Samples from infected root canals were collected, followed by anaerobic culture on CDC blood agar plates. After 7 days, colony forming units (CFU) were counted and isolated bacteria were identified by 16S rRNA gene sequencing. Results. The mean bacterial count (CFU) in root canals was (range ), and anaerobic bacteria were predominant (89.8%). The predominant isolates were Olsenella (25.4%), Mogibacterium (17.7%), Pseudoramibacter (17.7%), Propionibacterium (11.9%) and Parvimonas (5.9%). Conclusion. The combination of anaerobic culture and molecular biological techniques makes it possible to analyze rapidly the microbiota in infected root canals. The overwhelming majority of the isolates from infected root canals were found to be anaerobic bacteria, suggesting that the environment in root canals is anaerobic and therefore support the growth of anaerobes.